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3.10.4 plwf interface
A plwf plot contains the same information as a plf or plc plot; a plwf is like looking at terrain from a mountain peak, while plf or plc is like looking at a map. (Have you ever stood at a vista point, and used a map to identify and understand the "real" scene you are seeing? Would you rather have a photograph of the vista or a map to guide you through unfamiliar terrain?)
Like plc, plwf needs point centered z values on a quadrilateral mesh. A scale factor relating the units of z to the units of x or y may be specified via keyword; if not, plwf chooses a scale factor to make the range of z values half of the larger of the ranges of x and y. Other keywords allow you to choose whether or not the mesh lines will be drawn, and whether the surface itself will be shaded according to the scene lighting, or simply left the background color. (The latter choice results in a wire frame plot, which is the wf in plwf.)